1. Field of the Invention
The present invention relates to a flute mouthpiece, and, more particularly, to a flute mouth-piece in which a sound cannot possibly be confined inside or become unclear, and with which a clear, vigorous, rich, and loud quality sound can be produced at all times.
2. Description of the Prior Art
The present inventor has already studied and invented a flute mouthpiece designed to produce a rich, good quality sound by dividing the interior space of a pipe into two parts, including an acoustic space and a fluid space, by forming a projecting tongue.
More specifically, in the flute mouthpiece 2a shown in FIG. 1, in which a continuous inner surface extending from an edge 4a through the inner surface of a hole 3a to the upper portion of an inner surface 5a of a head pipe 1a is formed to be a streamlined surface 6a to produce a laminar flow free of any turbulence. The inner surface of the hole 3a on this side, on which the lip is to be placed, is made to extend downward into the head pipe 1a to form, on the inner wall of the head pipe 1a, a projecting tongue 11a, the lower surface of which is formed by a concave curved surface 12a, so that the interior space of the head pipe 1a is divided into two parts including an acoustic space A and a fluid space B.
An exhalation 7a sent through the gap between the lips is trained against the edge 4a and is therefore divided into halves as indicated by an inside vector 8a and an outside vector 9a. The air stream indicated by the inside vector 8a then flows along the edge 4a, the streamlined surface 6a, and the inner surface 5a of the head pipe 1a in this sequence. It is to be noted that a sound is produced when air blown against the edge 4a vibrates vertically in the acoustic space A. That is, the streamline indicated by the inside vector 8a becomes a laminar flow without forming any turbulence and, moreover, this flow swirls along the concave curved surface 12a of the projecting tongue 11a within the head pipe 1a and becomes a helical flow which, in turn, moves forward within the head pipe 1a. Due to this helical flow, an inward inflow vector 10a from the hole 3a toward the inner part acts to cause a type of vortex absorption, and this inflow vector 10a flows into a region of the fluid space B located below the projecting tongue 10a and has the function of joining the helical flow of the inside vector 8a.
In the case of the above-described flute mouthpiece, however, since the inner surface of the hole 3a on this side is made to extend downward into the head pipe 1a to form, on the inner wall of the head pipe 1a, the projecting tongue 11a, the lower surface of which is formed by the concave curved surface 12a, the interior space of the head pipe 1a is narrowed by the projecting tongue 11a. Since the fluid space B in particular is narrowed, the function of joining the inflow vector 10a with the helical flow of the inside vector 8a within the fluid space B is not sufficient and the vortex effect to which resistance to exhalation is reduced deteriorates, preventing a clear, vigorous, and rich quality sound from being obtained satisfactorily.
To cope with this, the present inventor has studied and invented another flute mouthpiece capable of eliminating the above-described problems.
More particularly, in the flute mouthpiece in FIG. 2, a projecting tongue 11a is provided such that, where the inner surface of a hole 3a on this side, on which the lip is to be placed, meets the inner surface of a head pipe 1a, a bulgy rounded concave surface 12a is formed so as to bulge outward from the head pipe 1a, and the interior space of the pipe head 1a is divided into two parts including an acoustic space A and a fluid space B.
In the case of the above-described flute mouthpiece, since the fluid space is expanded outwardly to become a bulging enlarged space, a vortex effect resulting from the helical flow generated in the fluid space is great enough to obtain a sufficiently clear, vigorous, rich, and loud quality sound. However, it was found that, since the degree of taper of the undercut of the hole 3a of a mouthpiece 2a is excessively large, the high-pitched tones of the scale of the flute are not true and the highest pitched tone is not produced. It was also found that the straight travel property of a sound wave deteriorates, so that a sound is confined inside.